We live in a time when what should be happening is that the government is printing money to enable a renewable energy/energy conservation revolution, turning every home into a super-insulated power station. But as you may have noticed, that’s not happening. While most of us sit and complain about this, in an ordinary house, on an ordinary street in Walthamstow in London, Dan Edelstyn and Hilary Powell decided to do something about it.